| 摘要 |
PURPOSE:To improve the selectivity of heat treatment by providing selectively a film of prescribed thickness on the occasion when the substrate is subjected to the heat treatment by using laser beams. CONSTITUTION:A polycrystalline Si layer 3 is formed on an Si oxidized film 2 provided on the surface of the monolithic substrate 1, a resistant layer 5 is formed thereafter by doping impurity atoms on the surface of the layer 3, forming by etching is conducted in prescribed dimensions and shape, and then an Si nitride film 21 having the thickness of lambda/4n (lambda is the wavelength of the laser beam and n is the refractive index of the film) is formed selectively on the surface. Aftrwards, the laser beams from a YAG laser and the like is applied to diffuse impurities under the nitride film 21 inward, whereby a region 23 is formed. By forming the single-layer film 21 in the thickness of nonreflective condition in this way, it becomes possible to conduct heat treatment with excellent selectivity and high precision. |
